Brittany

Question

Can you stop Evolution?

Initial Model

Brittany_inital_model_bubbl.jpg








Claim

Evolution cannot be stopped unless you can simultaneously extinguish the crossing over of genes, environmental change, and DNA mutations, which you cant.


Evidence

When an organism reproduces to add an individual to the population, there are many factors that affect the genetic makeup and survival of that creature, such as DNA mutations, the crossing over of genes, and changes in the environment that could affect their development and survival. When going through the cellular process of meiosis the process of crossing over occurs, and during prophase I, it occurs frequently. this crossing over allows for the re-assortment of two out of the four gametes, and it assures variation. After the organism is formed DNA mutations are constantly being formed, though some were produced as the organism was being formed. The DNA is changing constantly, and mutations like germ-line mutations are made and will soon be passed on to future generations, as they were passed down to this generation. The DNA mutations and crossing over can either be beneficial or detrimental to an organism, especially if they are in an environment that has changed for the best, or for the worst. There are many other factors of similar nature, but in general these are the factors that are stated in the Hardy-Weinberg Equilibrium, which states that if an infinitely large Random mating population is free of outside evolutionary forces, then gene frequencies will not change over time. His theory can be summed up by the following punnet square:


Females
A (p)
a (q)
Males
A (p)
AA (p^2)
Aa (pq)
a (q)
aA (qp)
aa (q^2)
All of these factors, or the lack thereof, lead to the process of natural selection, which is when organisms better adapted to their environment tend to survive and reproduce. Natural selection leads to the survival of the not-too-fit, where the weakest get picked off, and the strongest are prized by hunters that hunt for the best, such as humans. all of these factors add up to produce evolution.


Watch the video from 7:20 to 10:05

Sources:

http://anthro.palomar.edu/synthetic/synth_2.htm
http://www.ndsu.edu/pubweb/~mcclean/plsc431/popgen/popgen3.htm
http://www.ndsu.edu/pubweb/~mcclean/plsc431/popgen/popgen5.htm
http://www.youtube.com/watch?v=S9bHGXVBpHg



Final Model

1875tqxh_New-Sheet.jpg




Reasoning

The reason that evolution cannot be stopped is clearly stated and best explained by Darwin himself when he says "...individuals with the best genetic fitness for the environment will produce offspring that can more successfully compete in that environment. Thus the subsequent generation will have a higher representation of these offspring and the population will have evolved." what Darwin is basically saying, is that there are process that will inevitably lead to the process of natural selection, such as DNA mutations, crossing over of genes, and environmental change. As stated by the Hardy-Weinberg Theory, it is highly unlikely that one of these conditions will go away, and theoretically impossible that all conditions for evolution will just disappear. Organisms will produce, but not all of them. After multiple Evolutionary forces, such as DNA mutations, act on the organisms, the not-too-fit of the population will have survived, and they will be the ones to pass down their traits to the next Generation, eventually changing, if even slightly, the genetic make-up of that specific population. This is evolution, and this proves that it cannot be stopped.

Caleb


Question

Can you stop evolution?

Initial Model


1878ldac_New-Sheet.jpg

Claim

Because mutations and the causes of natural selection cannot be stopped, evolution cannot be stopped.

Evidence

Hardy-Weinberg's Model includes that mutation and non-random mating must be stopped to reach a stop to evolution.As told by Dr. Amanda Toland, "Our cells have built in
mechanisms that catch and repair most of the changes that occur during DNA replication..." This shows, as she later describes, that we are unable to completely stop
making mistakes in our DNA copying processes which lead to mutations, seen by the fact that our bodies are already trying to stop mutations but yet they are still present.
Natural Selection is a process involving the four previously described parts. As the environment changes a/ multiple traits are favored more so than the previously favored by
the environment's characteristics. This is seen in natural selection where, through the four specifications, the animals that are least fit for survival in the given environment die
before being able to reproduce. This causes a specification of traits to occur in the population affected by the environment. Since you cannot stop the environment from
changing either, the population will continue to evolve and cannot be stopped in this process.
http://www.genetichealth.com/g101_changes_in_dna.shtml

Final Model

dogst.JPG


Reasoning

Told by Hardy-Weinberg Equilibrium mutation and selective mating are some of the things that have to be stopped to reach a stopping point to evolution.
Because mutations, shown by Dr. Toland, and the environment, shown by historical evidence, are both unable to be stopped,
evolution will not cease to occur. Through mutations caused by genetic copying mistakes and natural selection, led by environment's
favoring, evolution cannot be stopped.